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NLC 2017-08-01/02

BAA report

The report to the BAA Aurora Section gives an overview of the night, which times were cloudy, free of NLC, or with sightings of NLC.

Name of observer: Horst Meyerdierks
Location: Royal Observatory Edinburgh, 55.9N 3.2W
          unattended compact camera with limited field of view
          A ~325-35, h ~0-40; images every 15 min
Date: 2017-08-01/02

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:00:05  0                                  cloud to h 15
21:15:05  0                                  cloud to h 10
21:30:08  X                                  cloud to h 20 or 25
21:45:10  0                                  cloud to h 15
22:00:32  X                                  cloud to h 10 or 15
22:15:53  X                                  cloud to h 10
22:31:24  I           2    7       325  340  cloud to h 4
22:46:24  X                                  cloud to h 5
23:01:24  II          2    3         5   20  through cloud
23:16:24  II          2    3         5   20  through cloud
23:31:23  II          1                      through haze, cloud at h 15 to 30
23:46:24  X                                  haze to h 5
01:02:33  II          2    2         0       haze on horizon
01:17:33  II          2    4                 through cloud
01:32:33  II          2    4                 through cloud
01:45:47  II          3    4                 through cloud
02:01:24  X                                  some cloud to h 5
02:15:53  I           1    7                 cloud below
02:30:33  II          2    6       330  340  through cloud
02:45:32  0                                  cloud to h 5
03:00:10  0                                  some cloud
03:15:02  X                                  cloud to h 10
03:30:01  0                                  some cloud
03:45:02  0                                  some cloud

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: other than or multiple of I-IV
       0: no NLC
       X: no decision possible (mist, cloud etc.)
brightness: 1: very weak
            2: clearly detected
            3: clearly visible
            4: very bright
            5: extremely bright

NLCnet report

The periods of positive sightings of NLC are reported to the NLC Observers' Home Page:

Name: Horst Meyerdierks
Country: Scotland
Location: Edinburgh
Date: 2017/08/01-02
Start: 22:30
End: 02:30
Forms: I,II
Max elevation: 7
Max brightness: 3
Comments: Through cloud.
http://www.chiandh.eu/nlccam/20170801-02.shtml

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: other than or multiple of I-IV
brightness: 1: very weak
            2: clearly detected
            3: clearly visible
            4: very bright
            5: extremely bright

Images

Listed below are the images with positive sightings of NLC. These have been processed merely to adjust the brightness for underexposure. For some, there may also be an unsharp-masked version of the image.

   UT      exp    A    hSun  h15   h85  stretch  image   (masked)
-------- ------ ----- ----- ----- -----  ----- -------------------
22:31:24 30.000 333.8 -12.9  -3.7   8.7  0-255 q4862.jpg
23:01:24 30.000 340.9 -14.5  -4.7   4.8  0-255 q4874.jpg
23:16:24 30.000 344.6 -15.1  -5.0   3.7  0-255 q4880.jpg
23:31:23 30.000 348.2 -15.6  -5.3   2.9  0-255 q4886.jpg
01:02:33 60.000  10.8 -15.8  -5.4   2.8  0-255 q4899.jpg
01:17:33 60.000  14.4 -15.3  -5.1   3.4  0-255 q4905.jpg
01:32:33 60.000  18.1 -14.7  -4.8   4.4  0-255 q4911.jpg
01:45:47 15.000  21.3 -14.1  -4.4   5.6  0-255 q4915.jpg
02:15:53 15.000  28.4 -12.3  -3.4  10.7  0-255 q4928.jpg m4928.jpg
02:30:33  8.000  31.8 -11.3  -2.8  16.6  0-255 q4933.jpg m4933.jpg

exp: Exposure time in seconds (200 ISO, f/2.8).
A: Azimuth of the Sun (degrees).
hSun: Altitude of the Sun (degrees, negative below horizon).
h15: Max. altitude of sunlight at 15 km height (degrees).
h85: Max. altitude of sunlight at 85 km height (degrees).
stretch: Contrast stretch (0-255 means no stretch).